1862 saw both sides win significant victories and suffer serious defeats on the battlefield. 1863, however, can be viewed as the year the Confederacy began losing the Civil War. The Emancipation Proclamation made freeing slaves an explicit war goal, effectively preventing European powers, notably Great Britain, from recognizing and supporting the Confederacy. Ulysses S. Grant's victory at the Siege of Vicksburg secured Union control of the Mississippi River. The Battle of Gettysburg ended Confederate hopes of winning the war through an invasion of the North. The Battle of Stones River, the Tullahoma Campaign, and the Chattanooga Campaign would drive Confederate forces from Tennessee and set the stage for William T. Sherman's Atlanta Campaign the following year.